The immune system can be divided into natural resistance, non-specific immune system and specific immune system. Natural resistance (primary defense line) refers to the anatomical and physiological components that block all intruders such as microbes regardless of their type. Further, Non-specific immune system (secondary defense line) refers to a defense system consisting of phagocytes that eliminate intruders which have broken the natural resistance and entered into a body. Also, specific immune system (tertiary defense line) refers to an immune system consisting of lymphocytes. Among them, specific immune system is a highly developed immune system having memory capacity and the ability to distinguish between self and non-self (Richard A. Goldsby, et al., KUBY Immunology, 2000).
Leukocytes constitute a secondary or tertiary defense line and take charge of foreign bodies that have broken the primary defense line. In the case of bacterial or viral infection or inflammatory reaction, the regulation of activities of macrophages and lymphocytes plays a crucial role in determining the therapeutic effect of a medicine. The macrophage is a main cell involved in the immune response, and known to serve various functions such as secreting cytokines to regulate the action of immune cells, destroying microbes, antigens, and dead tissues by phagocytosis in natural immunity, acting as an effector cell in humoral immune responses, eliminating antigens in delayed type hypersensitivity, destroying tumor cells by secreting Tumor Necrosis Factor-α (TNF-α), antigen processing and presentation in acquired immune responses, regulating immune responses by secreting inflammation-related substances or cytokines, healing damaged tissues by producing growth factors for fibroblast and vascular endothelial, etc. In addition, the macrophage plays a protective role against disorders such as infection and cancer, and secretes inflammatory cytokines and chemical mediators by inflammatory stimuli. Lipopolysaccharide, a membrane constituent of Gram-negative bacteria, is known to activate macrophages to secrete TNF-α, interleukin-1 (IL-1), IL-6, IL-10, prostanoids and nitric oxide.
Studies have been actively conducted to treat various disorders by enhancing immunity through regulating intracellular levels of the above-mentioned factors related to immunity, and initially, chemical substances were used to regulate intracellular levels of the factors, but they had a disadvantage of severe side effects, and recently, studies have been actively conducted to regulate intracellular levels of the above factors using nature derived substances which show no or very low side effects.
With regard to the above, Korean Patent Publication No. 2014-0019113 discloses a therapeutic or prophylactic activity of an α-galactosylceramide analogue on disorders due to abnormal immune modulation, and Korean Patent No. 10-1417341 discloses a composition for preventing and treating inflammatory or immune disorders comprising Sargassum muticum extract and an apo-9′-fucoxanthinone compound.
Meanwhile, it is known that Ceriporia lacerata is a kind of white-rotting fungus and conducts co-metabolism, i.e., lignin decomposition, in order to use carbon sources such as cellulose, hemi-cellulose, other polysaccharides, and glycerol, etc., in the ecosystem.
Regarding the use of Ceriporia lacerata in medical treatment, only the use of the extract of the culture medium of Ceriporia lacerata disclosed in Korean Patent No. 10-1031605 in the treatment of in diabetes is known so far. However, it has not been reported that Ceriporia lacerata has immune modulating effect yet.
Accordingly, the present inventors have found that an extracellular polysaccharide produced by Ceriporia lacerata; a mycelial culture medium of Ceriporia lacerata containing the extracellular polysaccharide; dried powders of the mycelial culture medium; or an extract of the mycelial culture medium shows immune modulating effect, and have completed the present invention.